//
// Created by DengLibin on 2019/1/4 0004.
//

/* J. David's webserver */
/* This is a simple webserver.
 * Created November 1999 by J. David Blackstone.
 * CSE 4344 (Network concepts), Prof. Zeigler
 * University of Texas at Arlington
 */
/* This program compiles for Sparc Solaris 2.6.
 * To compile for Linux:
 *  1) Comment out the #include <pthread.h> line.
 *  2) Comment out the line that defines the variable newthread.
 *  3) Comment out the two lines that run pthread_create().
 *  4) Uncomment the line that runs accept_request().
 *  5) Remove -lsocket from the Makefile.
 */
// tinyhttpd源码
/*

#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <ctype.h>
#include <strings.h>
#include <string.h>
#include <sys/stat.h>
#include <pthread.h>
#include <sys/wait.h>
#include <stdlib.h>

#define ISspace(x) isspace((int)(x))

#define SERVER_STRING "Server: jdbhttpd/0.1.0\r\n"

void accept_request(int);
void bad_request(int);
void cat(int, FILE *);
void cannot_execute(int);
void error_die(const char *);
void execute_cgi(int, const char *, const char *, const char *);
int get_line(int, char *, int);
void headers(int, const char *);
void not_found(int);
void serve_file(int, const char *);
int startup(unsigned short *);
void unimplemented(int);

*/
/**********************************************************************/ /*

 */
/* A request has caused a call to accept() on the server port to
 * return.  Process the request appropriately.
 * Parameters: the socket connected to the client */
/*

*/
/**********************************************************************/ /*

 void accept_request(int client)
 {
     char buf[1024];
     int numchars;
     char method[255];
     char url[255];
     char path[512];
     size_t i, j;
     struct stat st;
     int cgi = 0;      */
/* becomes true if server decides this is a CGI
 * program */
/*

char *query_string = NULL;

numchars = get_line(client, buf, sizeof(buf));
i = 0; j = 0;
while (!ISspace(buf[j]) && (i < sizeof(method) - 1))
{
method[i] = buf[j];
i++; j++;
}
method[i] = '\0';

if (strcasecmp(method, "GET") && strcasecmp(method, "POST"))
{
unimplemented(client);
return;
}

if (strcasecmp(method, "POST") == 0)
cgi = 1;

i = 0;
while (ISspace(buf[j]) && (j < sizeof(buf)))
j++;
while (!ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < sizeof(buf)))
{
url[i] = buf[j];
i++; j++;
}
url[i] = '\0';

if (strcasecmp(method, "GET") == 0)
{
query_string = url;
while ((*query_string != '?') && (*query_string != '\0'))
query_string++;
if (*query_string == '?')
{
cgi = 1;
*query_string = '\0';
query_string++;
}
}

sprintf(path, "htdocs%s", url);
if (path[strlen(path) - 1] == '/')
strcat(path, "index.html");
if (stat(path, &st) == -1) {
while ((numchars > 0) && strcmp("\n", buf))  */
/* read & discard headers */                                             /*
                                            
                                                         numchars = get_line(client, buf, sizeof(buf));
                                                     not_found(client);
                                                 }
                                                 else
                                                 {
                                                     if ((st.st_mode & S_IFMT) == S_IFDIR)
                                                         strcat(path, "/index.html");
                                                     if ((st.st_mode & S_IXUSR) ||
                                                         (st.st_mode & S_IXGRP) ||
                                                         (st.st_mode & S_IXOTH)    )
                                                         cgi = 1;
                                                     if (!cgi)
                                                         serve_file(client, path);
                                                     else
                                                         execute_cgi(client, path, method, query_string);
                                                 }
                                            
                                                 close(client);
                                             }
                                            
                                             */
/**********************************************************************/ /*

 */
/* Inform the client that a request it has made has a problem.
 * Parameters: client socket */
/*

*/
/**********************************************************************/ /*

 void bad_request(int client)
 {
     char buf[1024];

     sprintf(buf, "HTTP/1.0 400 BAD REQUEST\r\n");
     send(client, buf, sizeof(buf), 0);
     sprintf(buf, "Content-type: text/html\r\n");
     send(client, buf, sizeof(buf), 0);
     sprintf(buf, "\r\n");
     send(client, buf, sizeof(buf), 0);
     sprintf(buf, "<P>Your browser sent a bad request, ");
     send(client, buf, sizeof(buf), 0);
     sprintf(buf, "such as a POST without a Content-Length.\r\n");
     send(client, buf, sizeof(buf), 0);
 }

 */
/**********************************************************************/ /*

 */
/* Put the entire contents of a file out on a socket.  This function
 * is named after the UNIX "cat" command, because it might have been
 * easier just to do something like pipe, fork, and exec("cat").
 * Parameters: the client socket descriptor
 *             FILE pointer for the file to cat */
/*

*/
/**********************************************************************/ /*

 void cat(int client, FILE *resource)
 {
     char buf[1024];

     fgets(buf, sizeof(buf), resource);
     while (!feof(resource))
     {
         send(client, buf, strlen(buf), 0);
         fgets(buf, sizeof(buf), resource);
     }
 }

 */
/**********************************************************************/ /*

 */
/* Inform the client that a CGI script could not be executed.
 * Parameter: the client socket descriptor. */
/*

*/
/**********************************************************************/ /*

 void cannot_execute(int client)
 {
     char buf[1024];

     sprintf(buf, "HTTP/1.0 500 Internal Server Error\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "Content-type: text/html\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "<P>Error prohibited CGI execution.\r\n");
     send(client, buf, strlen(buf), 0);
 }

 */
/**********************************************************************/ /*

 */
/* Print out an error message with perror() (for system errors; based
 * on value of errno, which indicates system call errors) and exit the
 * program indicating an error. */
/*

*/
/**********************************************************************/ /*

 void error_die(const char *sc)
 {
     perror(sc);
     exit(1);
 }

 */
/**********************************************************************/ /*

 */
/* Execute a CGI script.  Will need to set environment variables as
 * appropriate.
 * Parameters: client socket descriptor
 *             path to the CGI script */
/*

*/
/**********************************************************************/ /*

 void execute_cgi(int client, const char *path,
                  const char *method, const char *query_string)
 {
     char buf[1024];
     int cgi_output[2];
     int cgi_input[2];
     pid_t pid;
     int status;
     int i;
     char c;
     int numchars = 1;
     int content_length = -1;

     buf[0] = 'A'; buf[1] = '\0';
     if (strcasecmp(method, "GET") == 0)
         while ((numchars > 0) && strcmp("\n", buf))  */
/* read & discard headers */                                             /*
                                            
                                                         numchars = get_line(client, buf, sizeof(buf));
                                                 else    */
/* POST */                                                               /*
                                                              
                                                                   {
                                                                       numchars = get_line(client, buf, sizeof(buf));
                                                                       while ((numchars > 0) && strcmp("\n", buf))
                                                                       {
                                                                           buf[15] = '\0';
                                                                           if (strcasecmp(buf, "Content-Length:") == 0)
                                                                               content_length = atoi(&(buf[16]));
                                                                           numchars = get_line(client, buf, sizeof(buf));
                                                                       }
                                                                       if (content_length == -1) {
                                                                           bad_request(client);
                                                                           return;
                                                                       }
                                                                   }
                                                              
                                                                   sprintf(buf, "HTTP/1.0 200 OK\r\n");
                                                                   send(client, buf, strlen(buf), 0);
                                                              
                                                                   if (pipe(cgi_output) < 0) {
                                                                       cannot_execute(client);
                                                                       return;
                                                                   }
                                                                   if (pipe(cgi_input) < 0) {
                                                                       cannot_execute(client);
                                                                       return;
                                                                   }
                                                              
                                                                   if ( (pid = fork()) < 0 ) {
                                                                       cannot_execute(client);
                                                                       return;
                                                                   }
                                                                   if (pid == 0)  */
/* child: CGI script */                                                  /*
                                                 
                                                      {
                                                          char meth_env[255];
                                                          char query_env[255];
                                                          char length_env[255];
                                                 
                                                          dup2(cgi_output[1], 1);
                                                          dup2(cgi_input[0], 0);
                                                          close(cgi_output[0]);
                                                          close(cgi_input[1]);
                                                          sprintf(meth_env, "REQUEST_METHOD=%s", method);
                                                          putenv(meth_env);
                                                          if (strcasecmp(method, "GET") == 0) {
                                                              sprintf(query_env, "QUERY_STRING=%s", query_string);
                                                              putenv(query_env);
                                                          }
                                                          else {   */
/* POST */                                                               /*
                                                              
                                                                           sprintf(length_env, "CONTENT_LENGTH=%d", content_length);
                                                                           putenv(length_env);
                                                                       }
                                                                       execl(path, path, NULL);
                                                                       exit(0);
                                                                   } else {    */
/* parent */                                                             /*
                                                            
                                                                     close(cgi_output[1]);
                                                                     close(cgi_input[0]);
                                                                     if (strcasecmp(method, "POST") == 0)
                                                                         for (i = 0; i < content_length; i++) {
                                                                             recv(client, &c, 1, 0);
                                                                             write(cgi_input[1], &c, 1);
                                                                         }
                                                                     while (read(cgi_output[0], &c, 1) > 0)
                                                                         send(client, &c, 1, 0);
                                                            
                                                                     close(cgi_output[0]);
                                                                     close(cgi_input[1]);
                                                                     waitpid(pid, &status, 0);
                                                                 }
                                                             }
                                                            
                                                             */
/**********************************************************************/ /*

 */
/* Get a line from a socket, whether the line ends in a newline,
 * carriage return, or a CRLF combination.  Terminates the string read
 * with a null character.  If no newline indicator is found before the
 * end of the buffer, the string is terminated with a null.  If any of
 * the above three line terminators is read, the last character of the
 * string will be a linefeed and the string will be terminated with a
 * null character.
 * Parameters: the socket descriptor
 *             the buffer to save the data in
 *             the size of the buffer
 * Returns: the number of bytes stored (excluding null) */
/*

*/
/**********************************************************************/ /*

 int get_line(int sock, char *buf, int size)
 {
     int i = 0;
     char c = '\0';
     int n;

     while ((i < size - 1) && (c != '\n'))
     {
         n = recv(sock, &c, 1, 0);
         */
/* DEBUG printf("%02X\n", c); */                                         /*
                                        
                                                 if (n > 0)
                                                 {
                                                     if (c == '\r')
                                                     {
                                                         n = recv(sock, &c, 1, MSG_PEEK);
                                                         */
/* DEBUG printf("%02X\n", c); */                                         /*
                                        
                                                         if ((n > 0) && (c == '\n'))
                                                             recv(sock, &c, 1, 0);
                                                         else
                                                             c = '\n';
                                                     }
                                                     buf[i] = c;
                                                     i++;
                                                 }
                                                 else
                                                     c = '\n';
                                             }
                                             buf[i] = '\0';
                                        
                                             return(i);
                                         }
                                        
                                         */
/**********************************************************************/ /*

 */
/* Return the informational HTTP headers about a file. */                /*
               
                */
/* Parameters: the socket to print the headers on
 *             the name of the file */
/*

*/
/**********************************************************************/ /*

 void headers(int client, const char *filename)
 {
     char buf[1024];
     (void)filename;  */
/* could use filename to determine file type */                          /*
                         
                         
                              strcpy(buf, "HTTP/1.0 200 OK\r\n");
                              send(client, buf, strlen(buf), 0);
                              strcpy(buf, SERVER_STRING);
                              send(client, buf, strlen(buf), 0);
                              sprintf(buf, "Content-Type: text/html\r\n");
                              send(client, buf, strlen(buf), 0);
                              strcpy(buf, "\r\n");
                              send(client, buf, strlen(buf), 0);
                          }
                         
                          */
/**********************************************************************/ /*

 */
/* Give a client a 404 not found status message. */                      /*
                     
                      */
/**********************************************************************/ /*

 void not_found(int client)
 {
     char buf[1024];

     sprintf(buf, "HTTP/1.0 404 NOT FOUND\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, SERVER_STRING);
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "Content-Type: text/html\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "<HTML><TITLE>Not Found</TITLE>\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "<BODY><P>The server could not fulfill\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "your request because the resource specified\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "is unavailable or nonexistent.\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "</BODY></HTML>\r\n");
     send(client, buf, strlen(buf), 0);
 }

 */
/**********************************************************************/ /*

 */
/* Send a regular file to the client.  Use headers, and report
 * errors to client if they occur.
 * Parameters: a pointer to a file structure produced from the socket
 *              file descriptor
 *             the name of the file to serve */
/*

*/
/**********************************************************************/ /*

 void serve_file(int client, const char *filename)
 {
     FILE *resource = NULL;
     int numchars = 1;
     char buf[1024];

     buf[0] = 'A'; buf[1] = '\0';
     while ((numchars > 0) && strcmp("\n", buf))  */
/* read & discard headers */                                             /*
                                            
                                                     numchars = get_line(client, buf, sizeof(buf));
                                            
                                                 resource = fopen(filename, "r");
                                                 if (resource == NULL)
                                                     not_found(client);
                                                 else
                                                 {
                                                     headers(client, filename);
                                                     cat(client, resource);
                                                 }
                                                 fclose(resource);
                                             }
                                            
                                             */
/**********************************************************************/ /*

 */
/* This function starts the process of listening for web connections
 * on a specified port.  If the port is 0, then dynamically allocate a
 * port and modify the original port variable to reflect the actual
 * port.
 * Parameters: pointer to variable containing the port to connect on
 * Returns: the socket */
/*

*/
/**********************************************************************/ /*

 int startup(unsigned short *port)
 {
     int httpd = 0;
     struct sockaddr_in name;

     httpd = socket(PF_INET, SOCK_STREAM, 0);
     if (httpd == -1)
         error_die("socket");
     memset(&name, 0, sizeof(name));
     name.sin_family = AF_INET;
     name.sin_port = htons(*port);
     name.sin_addr.s_addr = htonl(INADDR_ANY);
     if (bind(httpd, (struct sockaddr *)&name, sizeof(name)) < 0)
         error_die("bind");
     if (*port == 0)  */
/* if dynamically allocating a port */                                   /*
                                  
                                       {
                                           int namelen = sizeof(name);
                                           if (getsockname(httpd, (struct sockaddr *)&name, &namelen) == -1)
                                               error_die("getsockname");
                                           *port = ntohs(name.sin_port);
                                       }
                                       if (listen(httpd, 5) < 0)
                                           error_die("listen");
                                       return(httpd);
                                   }
                                  
                                   */
/**********************************************************************/ /*

 */
/* Inform the client that the requested web method has not been
 * implemented.
 * Parameter: the client socket */
/*

*/
/**********************************************************************/ /*

 void unimplemented(int client)
 {
     char buf[1024];

     sprintf(buf, "HTTP/1.0 501 Method Not Implemented\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, SERVER_STRING);
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "Content-Type: text/html\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "<HTML><HEAD><TITLE>Method Not Implemented\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "</TITLE></HEAD>\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "<BODY><P>HTTP request method not supported.\r\n");
     send(client, buf, strlen(buf), 0);
     sprintf(buf, "</BODY></HTML>\r\n");
     send(client, buf, strlen(buf), 0);
 }

 */
/**********************************************************************/ /*


 int main14(void)
 {
     int server_sock = -1;
     unsigned  short port = 0;
     int client_sock = -1;
     struct sockaddr_in client_name;
     int client_name_len = sizeof(client_name);
     pthread_t newthread;

     server_sock = startup(&port);
     printf("httpd running on port %d\n", port);

     while (1)
     {
         client_sock = accept(server_sock,
                              (struct sockaddr *)&client_name,
                              &client_name_len);
         if (client_sock == -1)
             error_die("accept");
         */
/* accept_request(client_sock); */                                       /*
                                      
                                               if (pthread_create(&newthread , NULL, accept_request, client_sock) != 0)
                                                   perror("pthread_create");
                                           }
                                      
                                           close(server_sock);
                                      
                                           return(0);
                                       }
                                       */
